In automotive body construction there is an increasing trend to use lightweight materials, or materials which offer higher structural performance per unit mass than low carbon or ‘mild’ steel, historically the material of choice for automobile bodies. A broad range of light-weight materials is currently in use including high strength steel, alloys of metals with lower density than steel, for example aluminum and magnesium, and polymers and polymer composites.
The initial use of polymers and polymer composites employed thermosetting polymers but, increasingly, attention is being focused on thermoplastic polymers which are beginning to supplant some of the earlier-adopted, alternative materials used in automobile bodies. Such thermoplastic polymers are meltable and heat formable and so may be shaped into a wide range of forms by application of heat and pressure. Suitably the thermoplastic may be shaped by being confined within an appropriately-shaped die cavity positioned internally to a heated, multipart die body and subjected to a shaping force applied to the die body by a press or similar machine.
All body components may be damaged in service, for example through forces generated by encounters with rough roads, potholes etc. during otherwise normal operation or under violent impacts such as may be encountered during collision. Where possible, it is desirable to repair any such damaged components. Preferably such repair may be performed in-place to limit the need for vehicle disassembly.